title: A human gastric cancer cell line possesses a functional receptor for gastrin-releasing peptide.
abstract: Bombesin (BBS) exhibits diverse biological functions including those of neurotransmitter, regulator of gastrointestinal hormone release, and mitogen. Gastrin-releasing peptide (GRP, the mammalian equivalent of BBS) is found in mucosal cells of the gastric fundus and antrum. We determined whether a human gastric cancer cell line (SIIA) expresses a functional GRP-receptor (GRP-R). BBS increased intracellular calcium ([Ca2+]i), and a specific GRP-R antagonist, ([D-Phe6, Des-Met14]-BBS (6-14)-ethylamide), blocked BBS-induced increase in [Ca2+]i. SIIA cells possess GRP-R mRNA by reverse transcriptase-PCR. Furthermore, these cells possess an 80-kDa cell surface protein that specifically binds BBS with two high-binding affinities (Kd1 = 0.6 nM, Kd2 = 6.7 nM). These findings indicate that SIIA cells possess a GRP-R that is capable of physiological signal transduction, though the cellular response remains unknown.
authors.affiliation: Department of Surgery, University of California, Davis-East Bay, Oakland 94602, USA.
authors.forename: R J
authors.initials: RJ
authors.lastname: Bold
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.forename: J
authors.initials: J
authors.lastname: Ishizuka
authors.forename: C M
authors.initials: CM
authors.lastname: Townsend
authors.forename: J C
authors.initials: JC
authors.lastname: Thompson
mesh_terms: D000230:Adenocarcinoma / Q000473:pathology*; D001839:Bombesin / Q000378:metabolism; D002118:Calcium / Q000378:metabolism; D003432:Cross-Linking Reagents; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D012333:RNA, Messenger / Q000235:genetics; D018004:Receptors, Bombesin / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000473:pathology*; D014407:Tumor Cells, Cultured / Q000473:pathology
chemical_list: D003432:Cross-Linking Reagents; D018076:DNA, Complementary; D012333:RNA, Messenger; D018004:Receptors, Bombesin; D001839:Bombesin; D002118:Calcium